Thread milling machine



Oct. 25, 1932. E, 1 LEES THREAD MILLING MACHINE Fjed Aug. 20, 1929 5 Sheets-Sheet l INVENTOR ATTORNEY Oct. 25, 1932. E J, LEES 1883,995

THREAD MILLING MACHINEL Filed Aug. 26. 1929 s sheets-sheet 2 INVENTOR Oct. 25, 1932. E. J. LEES THREAD MILLING MACHINE QQ 5 Sheets-Sheet INVENTOR A TO Oct. 25, E. J. LEES 1,883,995

THREAD MILLING MACHINE Filed Aug. 20. 1929 5 Sheets-Sheet 4 Oct. 25, 1932. E. J. LEES 1,883,995

THREAD MILLING MACHINE Filed Aug. 20. 1929 5 Sheets-Sheet 5 eti) Patented Oct.v 25, 1932 Vear ERNEST J'. LEES, OF CLEVELAND, OHIO, ASSIGNOB TO THE LEES-BRADNER-4GOMPANY,

OE' CLEVELAND, OHIO, A CORPORATION' OF OHIO i THREAD MILLING MACHINE Application filed August 20, 1929. Serial No. 387,222.

rlhis invention relates to machine tools and particularly to machine tools for performing a number of different operations on the same work piece and more particularly relates to machine tools for performing the operations of end facing and thread milling.

One of the objects of this invention is to provide a. machine and method for cutting threads, in an improved manner,V by means of a multi-ring type cutter. y

Another object is to provide a method and means for milling threads externally or internally of a work piece and on a generally conical surface thereof.

Another object is to provide a method and means for millingthreads on conicalrsurfaces to a higher degree of accuracy than heretofore attainable.

Another Objectis to provide a method and means for milling threads on conical surfaces whereby the positional relation of the beginning and end of the thread along the axis of the cone may be accurately determined.

Another object is to provide a method and means for milling threads on the conical surfaces of bodies having end faces or shoulders against which mating threaded portions are to be abuttingly oined in practice and Whereby the position of the beginning and end of the thread along the axis of the work piece relative to the end face or shoulder may be accurately determined.

Another object is to provide a thread milling machine of the type in which the lead of the toolrwith respect to the work is eifected by a gear driven lead screw and in which the prevent-ion of back lash in the gearing between sucessive threading operations is effect-ed'in an improved manner.

Another object is to provide in a thread milling machine of the class referred to an improved means for propelling the lead screw.

Another object istoprovide in a thread milling machine of the class referred to an improved means for transmitting power from the power source to the lead screw.

Another object is to provide in a machine adapted to perform an operation on a work piece along a line atan angle tothe axis of the workpiece, an vimproved means'for guidlng the tool along the said line.

Another object is to provide in a machine for cutting threads on conical surfaces an improved means for giving lead movement to the tool along a line at an angle to the axis of the work. .l

Another object is to provide in a machine adapted to operate on a Work piece on a line at an angle to the axis of the work and of the type in which the tool'may be fed relative to the work transversely of its axis, an improved means for adjustablyV feeding the tool and for eliminating lost motion in the guiding of the tool along said angular line.

Another object is to provide in a machine in which the tool may be given a longitudinal movement relative to the work to position it before operation thereon, an improved means f 7 for accurately so positioningthe tool.

Another object is to'provide a machine adapted to perform a facing operation on a4 work piece, and `in which a tool for performing a second operation such as thread milling or the like is adapted to be placed for engagei ment with the work in Vpositional relation to said faced portion, and having means for accurately so positioning the tool for the second operation. v

Another object is to provide an improved machine and method for accurately cutting threads by la milling cutter generally.

Anotherobj ect is to provide a thread milling machine in which lead movement is given to the tool support or carriage by means of a longitudinally traveling lead screw and by a clutch device adaptedto connect and disconnect the tool support orl carriage with the screw. 1

Another object is to provide, in a thread milling machine, improved means generally for propelling the tool support with a lead movement concurrently with theV rotary movement of the work supporting spindle.

Another object is to provide in a machine tool in which the tool may be given longitudinal movement relative to the worlrto position it before operation thereon,`means whereby the tool may be adjustably floated ion back and forth through the desired predetermined accurate position to positions beyond and to positions short of said positionV element, and a clutch device adapted to con-k neet and disconnect the lead giving element to orifrom the movable tool support (or work support) and by VaY movable element anchored on the machine Vagainst movement thereon inthe lead direction and engaged with Vthe lead giving element Jor moving it.

My invention is fully disclosed in the following description taken in connectionwith the accompanying drawings, in which :-V

Fig. 1 is a front elevational'vew ota machine embodying my invention;

Fig. 2 is an end elevational view of the machine of Fig. l taken from the right end thereof; Y

Fig. 3 is an end elevational view of the machine of Fig. 1 taken from the left end thereof; v Y

Figli is a rear elevational View of the machine'of Fig. 1; y

5v 'sa top plan. view of apart of the machine of Fig. 1, with portions thereof omit ted for simplicity; Y l

Fig. 6 is a view taken from the plane 6 et Fig. 1, with parts back of the section plane omitted for simplicity;

Fig. 7 1s a sectional view taken approximately rom the plane 7 of Figs. 1; e and 51;

Fig. 8 is a partial sectional View taken from the plane 8 of Figs. 1, l and 5;

Fig. 9 is a partial sectional View taken from the plane 9 of Figs. 1, l and 5;

Fig. 1() is a diagrammatic viewvo'lE a part of the power transmission mechanism of the machine of my inventionv and arranged approximately as viewed 'from above in F ig. i;

Fig.v '11 is a fragmentarysectional view of a work piece illustrating operations which may be performed by the machineV of Figs. 1 to 10; n c A Fig. 12 is a view similar to Fig. ll showing other operations which may be performed;

Fig. 13 is a sectional elevational view ot a micrometer gaging device shownv in elevation in Figs. 1 and 4i and drawn to a larger scale and with parts omitted for simpliiica- 1 tion; y p

Fig. la is a. transverse sectional view ot a push and pull bar which l employ for giving lead movement to a tool carrying slide;

ln the drawings I have shown at `1 the main bed et the machine. Mounted on the bed, and indicated generally at 6 in Figs. 1 and 4, is a work head provided with a hollow work spindle 7 rotatable in a bearing housing 8 and equipped at its opposite longitudinal ends respectively with Aa hand operable work gripping chuckl 9 and a pneumaticworlr Vgripping chuck 10. rnv 1 ine work to be operated on, which may be solid bars, tubes, pipe or the like, may` be passed through the bore of the work spindle and lgripped bythe chuck v9 and if longY enough also by the chuck 10..'

, ln the diagrammatic view;'Fig. 10, in which the parts are arranged, as if viewed from above in Fig. 1i, the Vhollow work spindle is indicated at 7 and a relatively short work piece 11 is shown gripped in the diagrammatically represented chuck 9. In Fig. l a wor-lr piecel? is shown.

of my present invention. f

Thechuclrs 9 and Y 10 may be orany known or suitable form of construction and constitute-no essential part-y The radially movable chuck jaws l2 ofthe i' chuck 9v are illustrated as operable by a plurality of screws 13 and the radially movable I 2, 3 and l-vmounted on the bed of the machine.. Power from the motor to rotatively drive the Y worlr spindle 7 `is transmitted by a chain or like means concealed inthe housing 1'9y to and through a system ot gearing and clutches for engaging and disengaging and changing the speed ratios or" the gears.r

l This transmission mechanism inthe elevaf tional views of the machine, Figs. 1 to 4 inclusive; is concealed in thefhousingsindi-r cated on the right endof the machine asm'y viewed in Fig. 4e. VThese power transmission connections, however, are indicated diagrarnf4 matically 1n Fig. 10. ln view of the develop` ment of this art, i is believed that the -olf lowing brief description thereof will be suf#` icient.

. The motor driven wheel 2Q is connectedto` a driving shaft 21 through a clutch'QQ. By i gears 23 and 2li a counter-shaft 25. is drivengz Gears 2S and 27 selected by a shifter 28 may selectively drive a gear 29 at high speed or,-v through anintermediate'gear 30; may drivev a gear Blat low speed and in the reverse direction and thus driving in alternate directions and at high .and low speeds a `shaft From the shaft 32, which'Y thus hastwo speeds and two directions; power may be talren through the beveled gears 33 and clutch l si, gears '35 and se tothe shaft 37; or Afrom lll) ' gears 51 ,or 52 thereon.

the shaft 82 power may be taken through the worm and Vworm gear 88, shaft 89,' speed change gears 40 and 41 and clutch 42 to drive the shaft 37.

The shaft 37 drives the work spindle 7 through a worm 48 and a worm wheel 44 which maybe thrown into and out of driving connection with the spindle 7 by a main clutch 45. Thus, it will be seen that the work spindle may be driven at high speed in one direction and at low speed in the other direction and that these speeds may be adjustably varied, and that all the speeds of the work spindle may be made relatively slow and suitable for a thread milling operation which may be performed on the machine. For rotating the work spindle 7 at generally higher speeds, and in one direction, the following drive is provided.

The power shaft 21 by means of a gear 46 drives a first intermediate shaft 50 by a gear 47. By means of the gear 47 and a gear 48 and a shifter 49, a second intermediate shaft 56 may be driven alternately by In either case, by means of a shifter 58 and selective gears 54 and engageable with. gears 56 and 57, a third intermediate shaft 58 may be driven; orV the shaft 58 may be driven through other selectedgears 59 or 60 by operating a shifter 61 to engage said gears with gears 62' or 63on the shaft 58. .In either case, a fourth intermediate shaft 64 may be driven by a gear 65 thereon and a gear 66 on the shaft 58. By means of a gear 67 on the shaft 64, th-e gear 68 on the work spindle 7V may be driven and by means of the main clutch 45, the gear 68 may be connected to the work spindle 7 to drive it.

It will thus be seen that by means of the gear 68 and its connection, the work spindle 7 may be driven at a great variety of speeds for a turning or facing operation, which may be performed on the machine.

For performing facing or turning operations on the machine, the mechanism which I provide includes many of the essentials of power driven lathes of known construction. As illustrated Vin Fig. 6, an apron 69 is mounted on upper and lowerways 70 and 85 disposed longitudinally of the bed of the machine and substantially parallel to the axis of the work spindle 7. Upon the apron may be supported a cutting tool 71.

By means of a transversely guided carriage 72 propelled by a handle 7 8 and screw, not shown,l and by means of a 'carriage 74 upon which the tool is mounted and which is movable both transversely of the machine by an operating handle 7 5 and screw, not shown, and adjustably rotatable on a vertical axis 200`and adapted to be locked in any adjusted position by a lever nut 201, the tool 71 be adjustably positioned relative to a rotating work piece such as the piece 17 in Fig. 1, in any ydesired position to perform thereon anend facing operation, or a. turning operation ory other lathe operation.

The means referred tofor positionally adjusting the tool 71 are here meagerly `described, but it is believed that these parts as illustrated in the drawings will. be recognized by those skilled in the art and no further description is required. Y

To give vlead movement to thel apro-n 69 along the ways 70 and 85, the hand wheel 76 may be operated or the apron may be lead by power from a shaft 77 driven through suitable gearing an'd clutches in the housing78, which are driven in a manner, not sho-wn, from a cross chain in the housing 79, Fig. 8, driven from the motor 18. e e

It is believed that this brief description will be sufficient for the lathe apron 69 and the tool 71 movable therewith, and thereon, inasmuch as these parts arewell lnownin con-` nection with lathes generally, and thus far considered form no essential part of my invention. y e

In connection with a thread milling operation, which may be performed'on the machine and which will be described later, it is sometimes desirable to perform a. facing operation to provide on a work piece a shoulder o-r end face such as is indicated at 80 in Fig. 11 or at 81 in'Fig. .12. It thus becomes necessary to coordinate the operation formed by the lathe tool 71 with` the-'thread milling operation and for this purpose, I provide a stop, preferably onthe bed of the machine, one form of which `is indicated at 82, Fig. 1, for stopping thelead movement of the apron 69, and for thus accurately limiting and determining the cut of the lathe tool 71 in the axial direction of the work piece. x

rlhe stop 82 as indicated, is preferably of clamp-.form secured to the way 85 of the machine by a set screw 88, but'other positions for the stop and other means for securing it to the -hed of the machine may be employed.

Furthermore, if desired, graduations may be provided on the way or elsewhere adjacent the stop 82 to preselect its position on the bed. y

In operation, one characteristic use of the stop 82 is as follows: Having in mind the shoulder or end face to be produced on the successive work pieces by the tool 71, the tool is set with its cutting edge in such position that by feeding it radially toward the work it will be'fed into the work and cut the desired face or shoulder thereon. To perform this operation, the apron is first lead, as by hand, until it is stopped by the stop 82 and when in this position the tool is fed as above described. Another usevof the stop 82 is to first move the too-l transversely of the work. It then may be led into thework by lead movement of the apron to produce the desired end face or shoulder thereon, and to lead the 'ico ica

iin

tool Vthe apron is given lead movement until itis stopped on the stop A82. Other modes and sequences of operation may be employed but in any caseit will be observed that the shoulder or end face produced on successive Work pieces will have a predetermined positional relation to some iinaginary'transverse reference plane on thebed `of the machine..

Besides the lathe tool and its functions, just described, Athe machine is provided With a rotary to-olfor .performing such yoperations as thread milling, and the mechanism for bringing the tool into working relation to the Work piece and the control mechanism thereof will now be described.

Mounted for longitudinal recipro-catory movement on ways 85, 86, 87 and 88 is a tool carriage indicated' generally at 89, in Fig. 1. The carriage is provided with a longitudinal slide 90, supported .on the ways referred to.

YMounted on the longitudinal slide is a transverse slide 91 guided for ino-vement on the longitudinal 'slide by suitable guides 92 on the slide 91 and ways 93 on `the longitudinal slide. Supported on the transverse slide 91 is a rotarytool spindle 94C in which may be secured a too-l 95 which in the form shown and described is a rotary cutting tool of the multi-ring type.

The tool spindle 94 is rotatably mounted in a tool spindle head 96 supported on the trans` verse slide 91 and adjustable thereon in a horizontal plane to vary the direction of the nected by gears including speed change gears concealed in the housing 100 to the tool spinj dle to drive it and afly wheel 101 being associated with the drive for the usual purposes.

The transverse slide'91 may be propelled on the ways 92--93 to position the tool transversely or to feed it relative to the work `by means of a threaded nut element 103 depending from thecarriage body, Figs. 5 and 7, and a screw 104 threaded therewith. The screw 104 may be turned by a gear 105 con# nected therewith which in turn is connected toa hand wheel 102 by a pinion 106 on the hand wheel meshed with the gear 105.

The screw 104Ck is anchored against longitudinal movement by a collar 107 and a gear hub 108 on the gearv105 abutting upon the ends of a bearing 109. The bearing v109 is form-ed on one end of a rectangular bar 110 and disposed between the slides 90 and 91 and movable relative thereto.

Thus, the slide 91 may be vmoved 'trans-l versely relative to thebar 110 in adjusting 'the latter isV guided to move simultaneously 'its position by thehand wheel Y102 and the;A

transversely and longitudinally by tapercut- Y A ting guide elements,'to be described.

A graduated scale 111 may be provided on j the Agear hub 108fand in cooperation'with an index pointer 107 on the bar 110 may be em.-

ployed to accurately move the slide 91 to accuratcly feed orposition the tool 95 transversely relative to thelwork. Y

i The longitudinal slide 90 may be or led along the ways 851:0 88 by Ymeans of a. longitudinal rack 112', Figs. 5 and 9 mountpropelled ed on the bed of the machine and by means of a pinion 113 mounted inthe vslide 90' for rotation on a vertical'axis. pinion 118 and thus propel the slide," abevel gear 114e is secured tothe pinion 113 and To rotate the j meshed with a bevel pinion 115 Aadapted to be l' i Provision is also made for rotating the spur gear 116 by power to propel, the slide rotatably driven by a spur gear llmeshed with a spur pinion 117 connected to a Vhandv Wheel 11.8. rEhus, by turning the hand-wheel 'j in` either direction, the kslide 90 maybe propelled 'along the ways in either directiox'll.`

95 f j: byl power when desiredV and comprises the posed along the bed of the machine in the direction of movement of the. slide and adapt-V Y f 120 meshed withthe gear 116 upon the movel edto be drivingly connected to a spur gear ment of a hand lever 121, Fig. 1; and inasf j much as the engageable and disengagea-ble clutch connections for'such purposes are Wellknown in the art and constitute no essential part of my invention,.thev connections between theelever 121', shaft 119 and gear` 120 Ahav been omitted for simplicity. f

When the operation of thread milling, to 110 be described, is performed,provisionis made toflead the slide 90 longitudinally ,on its ways iosf by a push and pull bar 122l andmechanism'` l for moving the bar longitudinally in either direction, which will presently bedescribed.

The slide 90 mayv be-rigidly clutched or gripped to the bary 122 in any position of the.Y

slideY alongthel ways, yso that it ma be Vpropelled by the bar, 122 and by the ollowing mechanism illustrated in Fig. 8. I i

. Y As shown on that figure andl as shown separately in Fig. 14,the cross-sectional shape of the bar 122 is circular in the lower half 0r more, but in the upper halffisplanedoffv longitudinally to provide two clutch gripping faces 123 and 124, leaving asmall flat or circular face'125 onlthe upper medial portion.

rllhe upper side .of the bar is thus rendered wedge shaped incross-section. y 1

As shown in Fig.v 8, the slide 90-is provided with an upwardly opening box V126 in which is fitted a pair of clutch jaws 127 and 128, bored out on a horizontal axis to receive a stem 129 which is threaded as at 130 into the jaw 127 and has a shoulder 131 at which the stem 129 joins an operating shaft 132 terminating outwardly in a lever 133. The jaws 127 and 128 are thus guided by the bof.: 126 to have a limited axial movement relative to each other, and by giving suitable transverse shape to the jaws and the box the transverse bars may be prevented from rotation on the stem axis. Y

The upper open end of the box is closed by a plate 136. The lower inner opposing faces 137 of the jaws 127 and 128 coincide with the faces 123 and 124 of the bar 122. ln operation, when the lever 135 is turned, the screw 139 turns and draws the jaws 127 and 128 toward each other, the plate 136 preventing their riding upwardly on the bar 122 and therefore, causing the gripping faces 137 to grip the bar and lock it rigidly to the slide 9U.

During movement of the slide 90 longitudinally by either of the'meansreferred to, the

transverse slide 91 may beV concurrently moved transversely to cause the tool to follow a path at an angle to the axis of the worlt for any purpose such as to operate upon conical surfaces of a work piece. F or this purpose, the following means is provided.

On the rear side of the bed, lligs-4, 5 and 7, is bolted a horizontally disposed bracket 138 by means of a vertical leg of the bracket T-bolts 140 passing therethrough and having heads in horizontal T-slots 141 on the bed. On the bracket 138 is bolted, by a center bolt 142, a taper bar 143, which may be adjustably rocked around the bolt 142 and locked in any adjusted position by bolts 144144 passing through the bar 143 and through circular slots 145 in the bracket.

A rectangular taper slide 146, having a downwardl o en roove straddlin and slid- D ably litting the bar 143, is adapted to be reciprocated on the bar 143. At the center of the slide 146`is an upwardly projecting circular boss 147 fitting into a corresponding circular bearing in theA bar 110, hereinbefore described.

Passing upwardly through the center of the taper slide 14 is a locl bolt 148V having a head 149 engaging the slide 146 and at its upper end projecting upwardly through the bar 110 and on through an elongated slot 150 in the transverse slide91. At its upper extreme end, the bolt is threaded into a head 151 which spans the slot 150 and rests upon the side edges of the slot. The head 151 may be turned on the threads of the bolt 148 by a lever 152 which passes around and over the slide and terminates at the` opposite side or front of the machine in a handle 153.

TWhen the handle 153 is moved in one direction, say, to the right, Fig. 1 or 5, the head 151 will be loosened on the bolt 148 and then by means of the hand wheel 102, the transverse slide 91 may be positioned transversely. Then by moving the handle 153 in the other direction, the head 151 may be tightened and this will, by means of the bolt 148 clamp rigidly tpgether the transverse slide 91 (in which the slot 150 is formed), the bar 110 and the taper slide 146, sothat these parts become substantially a rigid unitary structure.

Subsequently, longitudinal movement of the main slide 90 will cause the taper slide 146 to react upon the taper bar 143 and, due to Vthe angularly adjusted position of the bar 143, will give tothe slide 91 a concurrent transverse movement, the combined longitudinal and transverse movements thus'v giving to the tool 95 on the slide 91 a movement on an angular line parallel'to the bar 143.

The above Vdescribed feature of locking together the transverse slide 91, the bar 110 and the taper slide 146, so that these parts movein unison independently ofthe intermediate adjustable screw and thread connection byA whichV the position of the slide 91 is adjusted to thus eliminate all lost motion or back lash intermediate these parts constitutes one ofthe essential features of my invention.

To accurately position the slide 90 longitudinally on the ways to accurately position the tool 95 relative to the work in the axial direction, for a purpose to be described, the following means is provided.

Mounted on' the work head and therefore stationary with respect to the bed, is' a gagev bar 154 having a longitudinal horizontally disposed rotational bearing 155. The bar 154 is preferably provided with a planular face 156, which is thus movable in a transverse plane on the machine. The longitudinal position of the face 156 may be adjusted by longitudinally adjusting the support 156i, F 5, for the bearing 155, adjustment slots 157-157 being provided in the support 156 for this purpose.

Adapted to cooperate with the bar 154 is a micrometer gage 157, shown in Figs. 1, 4 and 5, and indicated in simplitiedform in Fig. 13. rlhe gage 157 comprises a main housing 158 out of which projects al plunger 159 in a longitudinal horizontal direction at a level somewhat above the aXis of the work spindle, and preferably at the level of thebearing 155 efthebar154. Y j

lnternally of the housing 158, as indicated in 13, a head 160 of the plunger engages linger 161 of a lever 162l pivoted on astationary pivot 163. The'freeend ofthe lever 163 has a slot embracing a pin 164 on a lever pivoted atene end on a stationary pivot 165,

the other end of which carriesa'pin 166 embraced by a slot in thefree end ofa lever 167, also pivotedv on the pivot 163. y

Rigidly connected on the' lever 167 is adia'l hand or pointer 168'. Upon movement of'tlie plunger 159 inwardly, theL levers are rocked around their pivots 163 and 165 in a well known manner and the pointer 168 will be moved around the pivot 167 greatly magni` fying the movements of the plunger 159. Any suitable means may lbeemployed to return the parts to the normal position shown in Fig. 13. Movement of the dial hand 168 may be indicated on a graduated scale 169 on the outside of the housing, Fig. 1, the position of the scale being adjustable on the housing by a set screw 170. The gage housing 158 is mounted on and movable with the transverse slide 91. The particular magnifying mechanism illustrated in Fig. 13 is not essential tomy invention, since other suitable or' known mechanisms may be employed to magnify the movement of the plunger 159.

In the operation of the machine, to be more fully described, the work piece to be operyated Von may be positioned relative to the gage bar v-154 and the plunger 159 may then be broughtl into contact with the bar face 156 by longitudinal movement of the slide and the plunger 159. will be pushed inwardly to cause the pointer 168 to indicate a predeter* mined reading on the scale 169 and thus a predetermined position .for the tool may be indicated, and thus the tool 95 may be, at successive operations, returned to a predetermined position on the machine relative to a preselected transverse reference planel on the machine.

The bar 154 may, by any suitabley friction or locking means be held in any adjustably rotated position. When it is disposed substantially horizontally, the plunger 159, because it is located approximately at the level of the bearing of the bar will engage the bar to indicate the position of the tool at all positions of the tool transversely of the machine, that is to say, the tool may be positioned longitudinally of the machine not only with respect to the transverse reference plane on the machine (the plane in which the bar 154 swings) but may be referred to the plane at any point in a horizontal line of the plane. It will be understood, of course, that after positioning the tool 95, the gauge bar 154 may be rocked upwardly out of the way.

To propel longitudinally the bar 122, as above referred to, the following' means is provided, shownY generally in Figs. 1 to 4 inclusive and indicated diagrammatically in Fig. 10.

Referring to Fig. 10, the rotary movement of the shaft 37 which, as above described, rotates the work spindle 7, also transmits movement through a worm 170 and worm gear 171 toa shaft 172. The shaft 172 runs the full length of the machine through the bed thereof, as shown in Figs. 6 to 9 inclusive, and at the left end of the machine, as viewed in Figs. 4 and 10, carries a gear 17 meshed with a gear 174 to drive meshed speed change gears 175 and 176 and a trans# mission shaft 177.

The shaft 177 may be connected to or dis- Y connected from a gear 178 by a sliding clutch 179 and gear 180 on the shaft 177. The gear 17 8 is .rigidly connected t'o-a nut 181 having an external cylindrical rotational bearing. j

surface 182 mounted rotatably in a bearing 183 secured to the main bed of the machine by the part broken away at 202.

The nut 181 is anchored against axial movement by a flange 184 on one end of the nut engaging one end of the bearing 183 and by a clamp nut 185 threaded on'the other end of the nut 181 between which andthe other end of the bearing 183 the gear`17 8 is clamped.

The adjacent end of the push and pull bar f 122 is threaded, as at 186, Figs. 4, 5 and 10 and meshed with'the internal threads of the nut 181. By this arrangement, rotation of the gear 178 rotates the anchored nut 181 and the nut rotating on the thread 186 pro-y pels the bar 122y longitudinally. It will thus be observed, particularly b reference to Fig. 10, that the rotary move-V ment of the work spindle 7, and the longitudinal movement of thebar 122 occur at `a fixed predetermined relative velocity ratio due to the gearing connections therebetween and that this ratio may be adjusted at will.

l In addition to the meansfor propelling i the bar 122 by rpower as above described, it

To accurately determine the rotational positiony of a work piece in the chuck 9, a graduated scale 187 may be provided 0n the periphery of the chuck, as shown in Fig. 1,

and to cooperate therewith a stationary index i' pointer 1.88 may be mounted on the stationary housing of the work head.

The operation of the machine of my invention will be described in Yconnection with the tool operations performed on the work piece 17, illustratedin Figs. l and 5 and i y shown separately in F ig.,11.

'The work piece is projected out of the chuck 9 a suitable distance, Figs. l'cand 5, which, if desired, may be roughly deter` mined by rocking the gage bar 154 to the c ik broken line position indicated in Figs.'1 andV 6, this being an auxiliary function of the gage bar which may or may not be utilized,

as desired.

After clamping thefxwork piece in thechuck, in this position, the lathe tool 71,

Figs. 1 and 6, which has previously been po-j sitioned on the apron 69 at the correct cutting angle, is moved, by movin y the apron, to bring it into engagement Witn'the end 'of the Work piece to face off the end face 80. The lead movement of the apron at this operation is stopped by the stop 82, which has been accurately set. Thus, the end face 80 is positionally related to a transverse reference plane of the machine.

VTo mill' the tapering threads 189 to th desired degree of taper, the angle of taper is first determined and the taper bar 14:3 is set at this angl-e, by means of graduations 190 on the bracket 138. The hand Wheel 102, Figs. 1, and 7, is then turned to position the tool 95k substantially coaxial with the Work piece 17, the lever handle 153, Figs. 1, 5 and 7, being first moved to loosen the lock bolt 148, Fig. 7, to permit movement of the slide 91.

The hand Wheel 118, Figs. 1, 5 and 9, is then turned to propel the slide 90 and to bring the tool 95 into the bore of the Work piece, the -position thereof axially in the bore being very accurately determined by the dial hand 168 on the scale 169, the hand being caused to move back and forth over the scale to the desired position by slight back and forth longitudinal movements of the slide 90 with the plunger 159 in engagement with the face 156 of the gage bar 154e, as shown in Fie'. 5.

t will be noted that the tool is not adjusted to its position by rigidly stopping the entire carriage unit (89 in Fig. 1), but that the carriage and tool may over-travel its final accurate position in either direction, thus gen* tly and Without shock and with high accuracy movingthe tool to its desired position.

lilith the axial positionof the tool 95 thus determined, thel motor 99 may be started to rotate the tool 95, and While rotating the transverse slide 91 is given a. transverse feed movement byturning the hand Wheel 102, Figs. 5 and 7, to feed the rotating tool to a predetermined depth into the inner Wall of the work, the predetermined depth being at# tained by a predetermined reading for the scale 111 and the index pointer 1107, Figs. 5 and 7. i

Then the tool has thus reached the desired depth, the slide 90 is connected rigidly tothe bar 122 by rotating the lever 133 to actuate the clutch mechanism, Fig. 8, to cause the l clutch jaws 127 and 128 on the slide 90 to grip the bar 122. The motor 18 is then started or the clutch 22, Fig. 10, engaged tosimultaneously start rotation of the Work spindle 7 and longitudinal propulsion of the bar 122 in the direction away from the Work to YWith-` draw the tool 95 gradually.

rEhe rate of rotation of the Work spindle and the rate of lead movement of the tool may be so predeterminedly related by the gearselection and changevgear connections,V

hereinbefore referred to, that the tool is advanced by the lead movement a distance equal tothe thread 'pitch during one revolution of the Work spindle, so that the several rings of the multier'ing cutter,all cuttingv simultaneously, cut the kcomplete conical spiral thread in one revolution of the Work piece.

Upon successively repeating the thread milling operation, on successive Work pieces, the tool is successively repositioned, as above described, by disengaging the clutch Which grips the bar 122 so that the bar 122 on successi-:e operations intermittently moves always in the tool withdrawing' direction, the clutch gripping it on successive operations farther and farther from the threaded end.

This mode of operation is an essential part of my invention. lf the more obvious mode of operation Were employed, namely to propel the bar 122 first in one direction and then in the other to respectively position the tool in the Work and then Withdraw it during the milling operation, great inaccuracy and a great loss of' time Would both result due to the great amount of back lash which Would be introduced in the train of gear connections by which the bar propelling nut 182 is rotated. But, by my invention, according to which the propelling nut is rotated always in one direction, this back lash is taken up on the first operation and thereafter the reintroduction of the back lash is prevented by continuing to rotate the propelling nut in one direction and propelling bar 122 in one direction. Thus, back lash between the propelling nut and the bar is likewise prevented.

As Will be understood, after a certain number of operations and longitudinal movement of the bar 122 in one direction, the length thereof will have been used upand Ya fresh beginning must be made, and this maybe done by rotating the nut 181 in the reverse direction and propelling the bar 122 back to a` starting position. This operation may be performed at -a rapid rate by the gear connections shown, particularly in Fig. 10, and if desired, Without rotating the Work spindle 7.

It is. therefore, one of the essential features of my invention that the nut 181 may be ro'- tated at a high rate of speed in thereturn direction. Its high speed rotationl accomplishes tivo results, namely the prompt return of the bar just mentioned and also the rapid removal of the back lash accumulated` in the gearing connections by which the nut is driven. lt Will be understood that the rate at Which the'nut 181 rotates during the thread milling operation is very slow and at 'great reduction of speed by reduction gearing and that it would be impractical to reverse the rotation of the nut between successive thread milling operations, because the attendant back lash in the reduction gearing would have to be taken up anew on each tool in the worlr.

reversal ot the nut, and in some casesthis would occasion a lost time interval of many minutes. But by means of my invention, the nut 181 may be slowly rotated always in one direction for repeated thread milling operations and at a. low speed; and at the end ot the's ries or' thread milling operations may be rotated at a. high rate `of speed to return the bar, and the unavoidable back lash referred to causes` no loss of time or other disadvantage in the operation of the machine.

It desired, ol course, the nut 181 may be rotated by handV as herein'beiorey described to return the'bar instead' ot by the power means.

It will be understood that taper threaded work piece, such as shown in 11, is intended to be screwed ,onto a mating piece,`

suchas shown in Fig. 12 with the end tace 8O abutting against a corresponding shoulder 81. Because the thread follows a `conical form, the beginning and ending or" the thread must be accurately positioned axially of the cone, otherwise the two mating pieces will screw up to a tight thread position betere the face 8O and shoulder 81 engage or vice I find, however, that with the machine of my invention, the face SO'and shoulder 81 may be' caused to come into tight mutual abutment exactly concurrently with the tightening of the two conical threads (male and female) with each other. The high degree ot accuracy neccssaryis effected by accurately relating the ace'SO on the work piece .with respect to a reference plane on the machine and subsequently accurately relating the conical thread axially with respect to the same plane or av plane parallel therewith at a predeterminetL distance therefrom by means ot the micrometer gaging device comprisin y or including the gauge bar 154 vand the tool ypositioning scale 169.

It, at any time, it be desired to retrace or' recut or chase a thread which has been cut, it may be desirable to accurately relocate the tool in the .work before sta sing the thread milling operation.I may be utilized when cut'- a ting tapering threads when the abutting end 'face 80 is not desiredtobe used. Y

The operation ot' thread milling liereinbefore described is performed by lead movement ofthe tool 95 in a withdrawing direction away tromthe work. It is one 'of the.

This be done with the milling operation in which Vthe tool is led longitudinally into or toward the work. v In this connection, the longitudinal positionof the tool 95 may ybe determined by the scalev 169 as in the other case, by abutting A the plunger 159 upon the gauge bar 154 and then i the gauge bar may be rotated upwardly 'out ot the path-of the plunger 159 and the gauge device 157 as a whole so that the tool may be led toward or into the work trom its starting position. Y In other words,l the Ytool is accurately positioned byy movement in one direction and operated by continued` movement in the same direction.

In.r connection with the retracing or recutting or chasing a thread which has beenicut or partially cut as above referred to, my invention has features of particular advantage when it is desired or necessary to move the tool carriage to a distance from the work. in some cases .fitter the threading operation has been performed, it is customary or dcsirable to insert a gauge such asa threaded gauge into the thread as cut totest its'accuracy and to make room for inserting the gaugeV into or upon the work, the tool carriage 89 Y f p Fi 1) may have to be removed to a distance on the ways to get the tool 9b out of the way.

This may be done by disengaging the clutch connection between the lead bar 122 and tool` carriage 89 l(shown in Fig. 8) andl freely moving` the carriageaway either by the hand after inspecting the work by means of the gauge, the tool may be re-set in thev thread 1001 wheel 118 or by the power Vshaft 119. Then.`

ot the work andthe longitudinal lead move-i"V Y ment of. the tool has been broken by disengaging the Vclutch as above referred to, the,V toolv maybe re-set in the work and atv'itsy former positionto a high degree `of accuracy by means of the gauge scales 187, `111 and 169 'referred to and 4upon reengaging the ,i

clutch between the carriage and the lead bar the rotary movement and the lead movement' may be resumed, and will'be in vthe Ksame harmony as before andthe tool may be chased through the thread already cutto .A ifinish it, or may be correctively readjusted to' 1 bring the thread more perfectly into conformity with the thread gauge, by which it was tested. The provision by which the tool 1 f may be entirely disconnected'from the `means for givingthe lead movement, and by which it may be moved independently thereof, as'for.-

example to inspect the work, and by, which it may-be again restored to working position,

andv its connection with the lead getting means 'reestablished without losingr itshar- ,monious relation to the work, and whereby it may accurately repeat or resume its thread cutting operation constitutes an essential feature of my invention.

While I have described the operation of my machine in connection with the thread milling of a conical thread of the internal or female type, as illustrated in Fig. 11, it will be understood that a tapering thread and a shoulder 8l may be produced on a work piece, as illustrated in Fig. 12 by the same general mode of operation and to the same high degree of accuracy.

Also while I have described my invention as particularly applicable to milling tapering or conical threads, it will be apparent that the advantages to be gained from the embodiment of the several features of my invention may be had in performing other and various operations on various kinds and classes of work pieces, and tapering and nontapering. Particularly, in this respect, I have illustrated and described my invention solely in connection with'a tapering tool of the multi-ring type, but those skilled in this art will, without further illustration or description, clearlyunderstand the use of my invention in its various phases with respect to a multi-ring cylindrical cutter or a single ring cutter, and my-invention,therefore, is not restricted to the use of a particular type of tool. Y

I have shown andy described my invention as embodied in a machine in which the work head is stationary on the bed of the machine and the tool carriage generally is movable relative thereto. The various features of my invention may be embodied to equal advantage in a machine of the type in which the tool is mounted on a stationary head on the bed of the machine and in which the work is mounted in a movable carriage, the essential requisite being to have the tool and the work movable relative to each other. Similarly, although I have shown the tool adjusting gage device as mounted and movable with the tool support and a stationary stop cooperating therewith as stationarily mounted on the work head, it will be apparent that in some applications of my invention, the position of these parts may be reversed.

Besides the foregoing indicated changes and modifications which may be made inthe foregoing embodiment and description of my invention, other and numerous changes and modications may be'made without departing from the spirit of my invention or sacriicing its advantages.

I claim:

l. In a machine of the class described, a support for a work piece, a tool support, a tool on the support, one of said supports being movable on the machine, means for setting up relative movement between a work piece on the work support and the tool support by movement of the movable support on the machine, means for accurately positioning the tool in working position relative to a 2. In a machine of the class described, a 4

support for a work piece, a tool support, a. tool on the support, one of said supports being movableron the machine, means for setting up relative movement `between a work piece on the work support and the tool sup- Y port by movement ofthe movable support on the machine, means for accurately positioning the tool in working position relative toa work piece on the work support, said means including la stop associated with one ofthe V supports, and a gauge device associated with the other of the supports, an indicator on the gauge device, van indicator operating element of the gauge device adapted torbe brought into engagement with the stop fby movement ,Y of the movable support in one direction and upon subsequent movement of the movable support. in either direction adapted to remain in engagement with the said stop and to indicate on the gauge device Y. the position of the tool at, short of, or beyond a preselected position.

3. In a machine of the class described, a support for a work piece, a movable tool carriage, a tool on the carriage, means for moving the tool carriage to move thetool into working position relative to a work piece on the work support, means foraccurately locating the tool, said locating means including a stop associatedwith the work support, a; gauge device on the tool carriage movable therewith, a position indicator on the gauge device, an indicator operating element of the gauge device, adapted to be brought into engagement with the stop by movement of the f tool carriage and adapted toremain in contact with the stop during continued movement and reverse movement of thetool carriage, to thereupon indicate on the gauge f positions of the tool beyond, at or short of?v a preselected position.

4. In a machine of the class described, a support for a work piece, a first tool support, a first tool on the first support, a second tool support, a second tool on the second support.: means for setting up relative rotary movement between a work piece on the work support and the first tool support to effect a relative operating movement between the first tool and the work piece, stop means for the ioo ilo

flrs't'tool support to determine a preselected :position between the lirst tool and the work piece relatively longitudinally, to thereby pro-vide'a worked portion on the worlr piece Shaving a predetermined relation-to a fixed Aao A' is -transverse reference plane on the lmachine, means for setting up relative rotary movement between the work piece and the second tool and concurrently a longitudinal relative movement to effect a thread cutting relative movement between the second tool and the Awork piece, means for positioning the second tool longitudinally with respect to the work pieceto cause the thread cutting operation to begin at a point having a predetermined positional relation longitudinally with respect to the said reference plane, said positioning means including a toolposition indicating gauge associated with theV second tool support and iXed'stop associated with the work support, the gauge being'adapted to indicate tool positions by engagement with the stop yupon relative movement between the tool support and' work support.

5. Ina machine of the class described, a rotary work spindle adapted to support a work piece, a rst tool support, a'tool on the iirst too-l support, lmea-ns for rotating the tool spindle, means for moving'the tool support longitudinal-ly of the work and transversely /thereof'to position the tool relative to the work for performing the operation thereon, stop means for determining the longitudinal position of the tool to establish on the work v.piece an operated portion having a predeterthe work support, a gauge device on the second toolsupport, Va gauge operating element of the device adapted to be brought into engagementwith the stop upon movement of the second tool support and adapted to permit continued movement of the second tool Ysupport while engaged with the stop whereby the gauge device may indicate positions voi? the tool beyond, at and short of a preselected tool position.

6. In a device for indicating the position of a tool'relative to a work piece on a machine tool, a work support, a stationary stop associated with the work support, a tool support,

,a tool position indicating gauge device associated with the toolsupport, an indicator element of the gauge device adapted to be moved into engagement-withthestop Vupon' adjustably moving the-tool support yand to indicate on the device positions,:ofthejtool` at, beyond and short of a preselected tool position upon continued movement of the tool' support toward and from the work support.

' 7. n a machine of the class described,- a tool support, a tool on the support, means for moving the tool longitudinally and `trans- .muy

versely of the machine to adjustably position 7 it, means for indicating positionsof thetool, said means comprising a gauge stop element movable in a transverse plane on themachine, and a gauge device Vassociated with tl1etool supportand adapted to be moved longitudi- .nally to engage the stop element at`any transverse position of the tool. Y Y I 8. In a-machine oi the class described,"`a

ltool support, a tool on the-support,means for moving the tool longitudinally andl transversely of the machine to adjustably position it, means for indicating positions ofthe tool, said means comprising a gauge stop velement movable in a tranverse plane on the machine. and a gauge'devic'e associatedrwith the tool'l support and adapted to be moved longitudnally to engage the stop elementratyany transverse position of: the tool, and the stop gauge .s device being adapted to be movedv out ofY the ,a i

longitudinal-path of the gauge device.v y 9. In a machine tool, the combination of a work support, a tool support, a tool on the tool support, means for positioning the tool relative to a work piece-on the work support means including a'gauge stop provided with a planular surface in a transverse plane on the machine, and a gauge device on the tool support movable therewith and operable by being moved into engagement'with the surface of the stop,vthe stop being mounted for movement to move the said surface in said plane and out of the path ofthe gauge device. 10. Ina machine of the class described, a; rotary'work spindle, a tool support, a tool on the support', means for rotating the work spindle and concurrently setting up a lead vmovement of the tool support toVefect a thread' cutting operation by the tool upon a worlr piece mounted on the work spindle, means for adjustably positioning the tool longitudinally with respect to the work piece at the beginning of the lead movement, said means comprising al gauge stop provided with a planular surface in a Vtransverse 'lane on the machine, an indicating gauge evice on the tool support movable therewith, a gauge operating element onthe device adapted to be moved by longitudinal movement, of the tool support into engagement with the said surface, and adapted by subsequent longitudinal movement of the tool-support toward andirom the'worlrto indicate positions of the tool at, beyond and short of; a preselected position, the stop being mountvto position it l'for 'operation thereon, said j i4-3 and from the spindle, both mounted on a base,

ed 'for amovement `out of the longitudinalV pathof the gauge operating elemeii'tfto permit-lead movement oftlietool support- 'and tool vinthe direction toward the work piece.

` 5 `11. 1n a machine of the class described,a

rotary work spindle,a tool support, a'tool onfthe support,means for rotating the work spindle and concurrently setting up a lead movement of the tool support to effect a at the beginning of the lead movement, said` means comprising a gauge stop provided with a planular surface in a transverse plane on the machine, an indicating gauge device on the tool support movable therewith, a

gauge operating element o-n the device adapt- 3 ed to be moved by longitudinal movement of the tool support into engagement with the said surface, the stop being mounted for movement out of the longitudinal path of the gauge operating element to permit lead movement of the tool support and tool in the direction toward the workpiece.

12. In a machine tool having a work support and a tool support, means for rotating one of said parts relative the other, and

tudinally relative the other, said last mentioned means comprising a lead screw keyed to one of said parts and axially movable in respect thereto, gripping means selectively securing said part to said screw, a nut held against axial movement, and means for rotating the nut.

13. ln a machine tool having a rotary work spindle and a tool support movable toward a threaded bar associated with said carriage and held against rotation thereby, a releas-y able gripping means for connecting the carriage to the bar to move axially therewith,

on said bar, and gearing between said work spindle and said nut.

14. A machine tool comprising a base, a

rotary work spindle carried thereby, a. tool supporting carriage slidably carried by said base, a non-circular lead bar passing through a non-circular opening in said carriage, the end of the lead bar being threaded, a nut threaded on the threaded portion of the lead H bar and journalled on the base, a gripping means for moving one of said parts longi-` J a nut journalled in said base and threaded bar and journalled on the basa-and a gripf jaw carried 'by lrsaid carriage-and arranged to clamp the same Ito the lead bar, 'and -p'os'i- "tive driving gearing between -thefwork spinvdle and -the nut.

16. Ina machine tool having a rotary work spindle and a tool support movable toward and from the spindle, both mounted on a base, a threaded bar associated with said carriage and held against rotation thereby, a releasable gripping means for connecting the carriage'to-the bar to move axiallytherewith, a ni'itjournalled in said base and threadedon said-bar, gearing between said work spindle and said nut, and means'for moving the tool carriagelongitudinally' with respect vto the lead bar when disengaged therefrom.

, -1.7. Ina machine tool having a'base, a'work support-,and a toolsupport carried thereby, means for moving one of said supportslongi- 'tudinally on said base, a guide carried-by the base and angularly adjustable relative the motion of said support, a transversely movable element carried by said support and having-one end slidable on said guide, asecond transversely movable element carried by said iirst transversely movable element, and'means for clamping said two transversely movable elements together. A

1 Y 1S. A machine tool comprising-a base, a rotatable work spindle carried thereby, aV

carriage slidable upon the base in thedirection of the axis of said spindle, an element slidable on said carriage transversely of'said axis, `an angularly adjustable guide carried by the base, the transversely extending -element being connected to a follower associated with said guide, a Asecond transversely movablevelement carried by said first transversely movable elementand supporting a tool, and

means for detachably connecting said transversely slidable elements together.

19. A. machine tool comprising a base, a rotatable work spindle carried thereby, -a carriage slidable upon the base in the direction oit the yaxis ot said spindle, an elementfslid-V 'able on Vsaid carriage transverselyotsaid Yaxis,ran angularly adjustable guide carried by the base, the transversely movable element havinga foll-owercontrolledA by said guide, a second transverse movable element carried by said first transversely movable element and supporting Ya tool, means for -detachably connecting said transversely slidable elements v'together, and means for moving the second transversely movable element relative the first transversely movable element. A j

20. A machine tool comprising a-base,r a

rotatable work spindle carried thereby, a carriage-slidable upon the base in the direction f of the axis of vsaid spindle, an element slidable on said carriage transversely of said aX-is, an angularly adjustable guide carried by the base, 'the transversely Ymovable element having a follower cooperating with said guide, a second transversely movable element carried by said iirst transversely movable elementV controlled by said guide, a second transverse- .ly movable element carried by said first transversely movable element andV supporting a tool, means for detachably connecting said j elements together, second transtransversely movable means for moving said versely movable member with relation to said first transversely movable member comprisinga threaded rod journalled in said first transversely movable element and threaded into the' said second transversely movable element, and means for rotating said rod.

22. In combination with a machine tool having a rotary Work spindle, a tool support,

and. means for` adjusting the position of the tool support axially of the spindle, for feedl ing the tool transversely the spindle, for rotating the Work, and for leading the tool tool axially the spindle, for feedingthe tool il transversely into the Work, forrotating theV Work, and for leadingthetool axially ofthe Work, distance-magnifying gaugeimeans inf dicating the original starting longitudinal poi sition |of the tool support.

In testimony whereof I signature thisv 6th day of August, 1929.

ERNEST J. 'n Y. i ,Ufff

`axially of the Work, gauge means indicating Y V starting longitudinal position of the tool suphaving a rotary Work spindle, a tool support, vand means for adjusting the position of the the original startingangular position of the Work spindle.

23, In combination' With a machine tool having a rotary Work spindle, a tool support,

and means for adjustingthe position of the tool axially the spindle, for feeding the tool transversely into'the Work, for rotating the Work, and for leading the tool axially of the Work, gauge means indicating the original port.

'24. In combination with a machine tool tool axially the spindle, for feeding the tool transversely int'o the Work, for rotating the Work, and for leading the tool axially of the Work, gauge means for indicating the orig- ,Y inal starting transverse position of the tool support. I

25. In combination with a machine tool means adjusting theposition of the tool axially and transversely the spindle, means forv feeding the tool transversely into the Work, for rotating the Work, and for leading the tool l axially of the Work, of gauge means for indieating the original position of the tool both longitudinally and transversely.

26. In combination With a machine tool having a rotary Work spindle, a tool support,

' and means for adjusting the position of the hereunto afiiix `A Y miAV 'los

having a rotary Work spindle, a tool support,

i mi

miy 

